I'm not saying that isn't a valid design tradeoff: I find it very appealing. But the hard consistency vs. availability problems are still there. If you're Ticketmaster running sales for a hot concert with this scheme, you'll have to send out "confirmation" emails that say: "Your order for four tickets has been received. It may or may not be fulfilled." Sure, your system is "available", but not in the sense that users are receiving useful answers to queries like, "Did I get tickets?"

The point is that this depends on your problem domain. If you're, say, Facebook, you don't really need consistency. It doesn't matter if some people sometimes see out of date data, or similar 'errors'. What matters is that your site is always up. The same goes for Google: they'd rather have a fast query that might be missing some inputs, than the same results for everyone, but slow.